tweaks that impress the unsuspecting


What I'm interested in are tweaks that impressed friends or significant others WITHOUT being told beforehand that the tweak was done...If they were tipped off first, it doesn't count.
desoto
One of the best tweeks bar none was the addition of an Auralex "SubDude" isolation platform for my sub. Best $50 ever spent on audio. Unbelieveable, kills any unwanted vibrations and resonances that muddy the sound.
I second Oddiofyl's observation re SubDude. With my Velodyne HGS-15 and HGS-10 the SubDudes removed the boom and extended the bass.

db